// 
// Copyright (c) 2008 Eric Czarny <eczarny@gmail.com>
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of  this  software  and  associated documentation files (the "Software"), to
// deal  in  the Software without restriction, including without limitation the
// rights  to  use,  copy,  modify,  merge,  publish,  distribute,  sublicense,
// and/or sell copies  of  the  Software,  and  to  permit  persons to whom the
// Software is furnished to do so, subject to the following conditions:
// 
// The  above  copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE  SOFTWARE  IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED,  INCLUDING  BUT  NOT  LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS  FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS  OR  COPYRIGHT  HOLDERS  BE  LIABLE  FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY,  WHETHER  IN  AN  ACTION  OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
// 

// 
// NOTE:  The  following  is  an  adaptation of code released by Dave Winer and
// Brent  Simmons.  Dave  Winer wrote the original Base64 encoding and decoding
// routines.  Brent Simmons adapted Dave Winer's code for use with Objective-C.
// These  extensions  are  simple  NSString  and  NSData additions that provide
// better NSIntegeregration NSIntegero this XMLRPC framework.
// 

// 
// Cocoa XML-RPC Framework
// NSStringAdditions.m
// 
// Created by Eric Czarny on Wednesday, January 14, 2004.
// Copyright (c) 2008 Divisible by Zero.
// 

#import "NSDataAdditions.h"

/* Base64 Encoding Table */
static char base64EncodingTable[64] = {
	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
	'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
	'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
	'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};

@implementation NSString (NSStringExtensions)

+ (NSString *)base64StringFromData: (NSData *)data length: (NSInteger)length {
	unsigned long ixtext, lentext;
	long ctremaining;
	unsigned char input[3], output[4];
	short i, charsonline = 0, ctcopy;
	const unsigned char *raw;
	NSMutableString *result;
    
	lentext = [data length];
	
	if (lentext < 1) {
		return @"";
	}
	
 	result = [NSMutableString stringWithCapacity: lentext];
 	
 	raw = [data bytes];
	
	ixtext = 0; 
 	
	while (true) {
		ctremaining = lentext - ixtext;
		
		if (ctremaining <= 0) {
			break;
		}
		
		for (i = 0; i < 3; i++) { 
			unsigned long ix = ixtext + i;
			
			if (ix < lentext) {
				input[i] = raw[ix];
			} else {
				input[i] = 0;
			}
		}
		
		output[0] = (input[0] & 0xFC) >> 2;
		output[1] = ((input[0] & 0x03) << 4) | ((input[1] & 0xF0) >> 4);
		output[2] = ((input[1] & 0x0F) << 2) | ((input[2] & 0xC0) >> 6);
		output[3] = input[2] & 0x3F;
		
		ctcopy = 4;
		
		switch (ctremaining) {
			case 1: 
				ctcopy = 2; 
				break;
			case 2: 
				ctcopy = 3; 
				break;
		}
		
		for (i = 0; i < ctcopy; i++) {
			[result appendString: [NSString stringWithFormat: @"%c", base64EncodingTable[output[i]]]];
		}
		
		for (i = ctcopy; i < 4; i++) {
			[result appendString: @"="];
		}
		
		ixtext += 3;
		charsonline += 4;
		
		if (length > 0) {
			if (charsonline >= length) {
				charsonline = 0;
				
				[result appendString: @"\n"];
			}
		}
	}
	
	return result;
}

@end
